The outsize-menswear chain High & Mighty is on the hunt for larger salespeople to offer "empathetic" service to its unusually shaped customers as it embarks on a rapid spate of openings to cater for Britain's bulging girth.

The chain stocks brands such as Polo by Ralph Lauren and Ben Sherman, specialising in waist sizes of up to 60in, inside legs of 38in, shoes up to size 17 and extra-large ranges as high as 6XL.

Citing demographic figures forecasting an increase in male obesity from 25% in 2008 to 30% in 2013, High & Mighty plans to grow from 14 stores to 25 outlets over three years, kicking off with openings in Liverpool, Newcastle and Belfast. Managing director Gill Politis, who at 5ft 10in is 7in taller than the average British woman, said that as the chain recruits, size would be an advantage: "In an ideal world, every one of our stores would be staffed by high and mighty people. I understand what the issues are from the perspective of a tall female. That's part of what we'd look for in someone coming to work for us."

Some 27% of men in Britain are more than 6ft tall, accounting for a 30% chunk of the menswear market worth £2.9bn according to analyst TNS. Twenty per cent have a waist of over 38in and 22% a chest size of 44in or higher, accounting for a market of £1.2bn-£1.4bn.

Founded in 1956 by tailor Bernard Levy, the chain ran into financial trouble two years ago and was forced to retrench rapidly. It slipped into administration before being bought for £1.6m in September last year by Manchester-based N Brown, which owns the home delivery firm JD Williams.

Politis said High & Mighty was also trying to work with suppliers on standardisation, to overcome a nagging problem – the wide disparities in manufacturers' definitions of "XL". The chain is also slightly lowering the minimum size of its stock to attract more mainstream customers: "We don't want to stigmatise customers by their size – we cater for tall, broad and muscular, well built men," she said.